FZ. Kristallogr. NCS 216 (2001) 1-2
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Crystal structure of mercury(II) trihydrogenhexaoxoiodate(VII),
HgH 3 I0 6
Th. J. Mormann and W. Jeitschko*
Universität Münster. A n o r g a n i s c h - C h e m i s c h e s Institut. W i l h e l m - K l e m m - S t r a ß e 8. D - 4 8 1 4 9 Münster. Germany
Received May 9. 2 0 0 0 , C S D - N o . 4 0 9 4 9 9
the acentric space group was defined by the position of the
mercury atom. The structure was also refined in the
centrosymmetric space group PI (No. 2): R = 0.071 for 1337
structure factors and 27 variable parameters. The inversion center
is destroyed by the uneven number of hydrogen atoms. These
were readibly located by a difference Fourier synthesis and their
positions could be refined by the full-matrix least-squares
program.
Discussion
Abstract
H 3 HgI0 6 , triclinic, PI (No. 1), a = 4.8085(7) Ä ,
b = 5.3115(7) Ä, c = 5.6116(8) Ä, α = 65.307(6)°,
β = 76.451(6)°, γ = 63.859(7)°, V = 116.7 Ä 3 , Z = 1,
Rgt(F) = 0.045, wR r e ffF 2 ) = 0.130, Τ = 293 Κ.
Source of material
HgHsIOö was obtained by precipitation reacting aqueous
solutions of 10.7 g of N a I 0 4 (50 mmol) in 10 ml 15 m HNO3 and
8.1 g (25 mmol) of Hg(N0 3 )2(H 2 0) in 4 0 ml 15 m HNO3 at
293 K. The colorless precipitate of HgHsIOö was washed with
isopropyl alcohol and diethyl ether, and dried at 333 K. An energy
dispersive x-ray flourescence analysis in a scanning electron
microscope showed no impurity elements heavier than sodium
and revealed an atomic ratio Hg:I = 1:1.
Experimental details
The lattice constants were determined from Guinier powder data
using α-quartz (a = 491.30 pm, c = 540.46 pm) as an internal
standard. They are slightly (on average 0.12 %) greater than those
determined on the four-circle diffractometer, because the latter
are affected by systematic errors due to absorption. The origin of
* Correspondence author (e-mail: [email protected])
The periodate HgHjIOe has been prepared already by Siebert and
Fuckert [1]. The crystal structure is reported here. In the triclinic
structure there is only one formula unit per cell. The mercury atoms are in linear coordination of two oxygen atoms with Hg—Ο
distances of206.4(7) and 206.7(7) pm. In addition the mercury atoms have six oxygen neighbors with considerable greater Hg—Ο
distances extending from 260.6(7) to 320.7(7) pm. These distances may be compared to the corresponding Hg—Ο distances
in the recently determined structure of the trimercury(II)
dihydrogenhexaoxoiodate(VII), Hg3(H2l06)2 [2]. In the latter
structure there are three independent mercury atoms, one of these
with tetrahedral oxygen environment. The short Hg—Ο distances
of the other two mercury atoms extend from 208.3(10) pm to
212.0(9) pm, somewhat greater than the short Hg—Ο distances in
the presently reported structure of HgHsIOö. However, these differences are compensated by the Hg—Ο distances of the other six
oxygen neighbors of both compounds. These have average
Hg—Ο distances of 283.3 pm in HgHsIOö and 273.0 pm and
273.6 pm in Hg 3 (H2l0 6 )2.
In both compounds the iodine atoms are octahedrally coordinated
by oxygen atoms with I—Ο distances ranging between 181.4(7)
and 193.8(8) pm in HgHjIOe, very similar to the range of I—Ο
distances from 181.1(10) to 194.3(9) pm found for the two independent iodine atoms in Hg3(H 2 I06)2· Using the bond-length and
bond-valence relations according to Brown [3,4] with the Ro and
Ν values of 1.942 and 5.8 the I - O bonds in HgHsIOö obtain bond
valences from 1.485 for the shortest to 1.013 for the longest I—Ο
bond. The total for all six I—Ο bond-valences amounts to 7.21, in
good agreement with the oxidation number of the iodine atom.
As could be expected, the oxygen atoms of the OH groups have
the longest I—Ο distances with 193.8(8), 192.3(8), and 190.0(8)
pm for I — 0 3 , 1 — 0 5 , and I—O6, respectively. The oxygen atoms O l and 0 4 , which are strongly bonded to the mercury atoms
have almost the same I—Ο distances with 186.1 (7) pm for I — 0 1
and 187.2(7) pm for I — 0 4 , and they are not bonded to other
heavy atoms. The bonding angles H g - O l - I and I - 0 4 - H g are
practically the same with 125.4(4)° and 122.4(4)°. The 0 2 atom
has the shortest I—Ο distance (181.4(7) pm); in addition to the iodine atom it has two mercury neighbors at 260.6(7) pm and
320.7(7) pm.
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2
Mercury(II) trihydrogenhexaoxoiodate(VII)
Table 1. Data collection and handling.
Table 2. Atomic coordinates and displacement parameters (in A").
Crystal:
Wavelength:
Atom
Site
X
y
c
O(l)
0(2)
0(3)
H(3)
0(4)
0(5)
H(5)
0(6)
H(6)
la
la
la
1a
la
1a
la
la
la
0.780(2)
0.542(2)
0.505(2)
0.58(5)
0.271(2)
0.870(2)
0.90(5)
0.173(2)
0.19(5)
0.426(2)
0.890(2)
0.129(2)
0.13(5)
0.579(2)
0.342(2)
0.31(4)
0.668(2)
0.61(5)
0.735( 1)
0.318(1)
0.667(2)
0.68(4)
0.241(1)
0.274(2)
0.35(4)
0.701(2)
0.79(4)
Diffractometer, scan mode:
colorless plate, size 0.02 χ 0.05 χ 0.05 mm
Mo Ka radiation (0.71073 A)
1
395 cm"
Enraf-Nonius CAD4, ω/2θ
29ma*:
MAtOmeasured.
79.82°
2789, 2786
μ:
N(hkl)un,qM'.
Criterion for /0b<·. N(hkl)sc
N(param)n fined:
/obs > 2 σί/obJ, 2673
50
Programs:
SHELX-97 (5), DIAMOND [6]
0.0121(9)
0.0116(9)
0.013(1)
0.020
0.013(1)
0.015(1)
0.022
0.014(1)
0.021
Table 3. Atomic coordinates and displacement parameters (in Ä2).
Atom
Site
X
Hg(l)
la
la
(f
KD
0.5221(1)
0"
0.5225(2)
ζ
i/ll
Uii
ί/33
0"
0.4825(1)
0.0160(3)
0.0084(3)
0.0118(2)
0.0067(3)
0.0127(2)
0.0088(3)
t/12
-0.0030(1)
-0.0026(2)
υ
t/13
-0.0048(2)
-0.0024(2)
-0.0017(2)
-0.0026(3)
a: arbitrarily fixed for definition of the origin.
References
1. Siebert, H.; Fuckert, M.: Neue Quccksilber(II)-periodate. Z. Anorg. Allg.
Chem. 433 (1977) 224-228.
2. Mormann, Th. J.; Jeitschko, W.: Crystal structure of trimercury(II)
dihydrogenhexaoxoiodate(VII), Hg3(H2l06)2· Z. Kristallogr. NCS 215
(2000)315-316.
3. Brown, I. D. : in "Structure and Bonding in Crystals", Vol II (Eds. M.
O' Keeffe and A. Navrotsky), p. 1 -30. Academic Press, New York, 1980.
4. Brown, I. D.; Altermatt, D.: Bond-Valence Parameters Obtained from a
Systematic Analysis of the Inorganic Crystal Structure Database. Acta
Crystallogr. B41 (1985) 244-247.
5. Sheldrick, G. M.: SHELX-97: A Program System for the Solution and Refinement of Crystal Structures. University of Göttingen, Germany, 1997.
6. Brandenburg, K.; Berndt, M.; Bergerhoff, G.: Diamond - Visuelles
Informationssystem für Kristallstnikturen. University of Bonn, Germany,
1996.
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